Communication Assisted Synchronisation Control in Three-Phase PV Integrated Voltage Source Converters

Synchronization control refers to the equalizing of phase, frequency, and magnitude of the voltage of the existing system to the connected network. The traditional synchronization of the utility grid involves matching the generator's speed and frequency to the voltage of the infinity bus. Whereas, in the context of microgrids, the process is even more challenging. It involves the generation of reference voltage signals for the microgrid converters powered by different sources by the accurate tracking of the grid voltage phase template. A synchronized output voltage requires an active inner current control loop. Current control methods enable the exchange of real and reactive power between the microgrid and the utility grid. This paper focuses on the simulation of a communication assisted current control in three-phase PV integrated Voltage Source Converters for grid integration. A communication tool (CAN) is used to implement the current control so that simultaneous synchronization of the two VSIs is possible. Simulation of the control is implemented in the DQ reference. The objective is to maximize the load sharing of the converters, reduce harmonics, and provide a stable transient response. The system performance is also tested in both grid-tied and islanded modes.